Collecting electrode for electrical precipitators



c. B. CLYNE 1,773,951

COLLECTING ELECTRODE FOR ELECTRICAL PRECIPITATORS Aug. 26, 1930.,

Filed Dec. 11, 1926 2 Sheets-Sheet I. I I

IN V EN TOR. CFLI/ 5. 65! BY f? w ATTO EYS.

Aug. 26, 1930. c, B, CLYNE 1,773,951

COLLECTING ELECTRODE FOR- ELECTRICAL .PRECIPITATORS Filed Dec. 11, '1926 2 Sheets-Sheet 2 INVENTOR.

, ATi'ORN s.

Patented Aug. 26, 1930 UNITED STATES PATENT" OFFICE CECIL B. CLYNE. OF. BEVERLY HILLS, CALIFORNIA, ASSIGNOR TO INTERNATIONAL PRECIPITATION COMPANY, 01 LOS' ANGELES, CALIFORNIA, A'CORPORATION OI CALIFORNIA COLLECTING ELECTRODE FOR E ECTRICAL PRECIPITATOBS Application filed December 11, 1926. Serial No. 154,228.

This invenion relates to apparatus for electrical precipitation of suspended particles from gases and particularly to a novel con struction of collecting electrode for use in such apparatus. i

The chief object of the invention is to provide a collecting electrode of the plate type which may be simply and economically constructed and which combines good electrical properties with advantageous mechanical properties making it especially adapted for use in electrical precipitation.

It has theretofore been proposed. in United States patent to F. H. Viets, No. 1,569,595, to cast each collecting electrode as an integral slab or plate of concrete or other electrically semi-conducting cementitious material with a metallic supportii'lg member at one edge thereof (such edge being the top of the electrode when placed in position for use) and with metallic recnforcing members connected to said metallic supporting member and extending perpendicularly thereto and embedded within the material of which 'the plate is formed so as to extend vertically when the plate is in position for use and serve as embedded conductors for the electric current as well as reent'orcing means. It has been found, however that plates constructed in this manner have a marked tendency to warp or buckle when hot gases are passed in contact therewith. and as these electrodes are usually of relatively large dimensions, for example, 8 to 12 feet in vertical length, such Warping causes an appreciable lateral displacement between the top and bottom and the intermediate portion of the electrode. In certain cases this displacement has been found to be as great as an inch or more and as the spacing between the collecting electrode and the adjacent discharge electrode members is usually about 3 or at inches,'n'iore or less, it is obvious that this lateral displacement of portions of the collecting electrode may often cause serious disturbances in the electrical field. Certain portions of the collecting electrode are brought much closer tothe discharge electrode members than other portions, so that the electrical'field not uniform throughout all portions of the collecting electrode surface and there is a tendency to arcing or disruptive discharge at the portions of the collecting electrode which are displaced toward the discharge electrode members, particularly in case of accumulation of a deposit of precipitated material upon such portions of the electrodes. This objection maybe overcome by forcibly cracking the collecting electrode plates along a plurality of equally spaced lines perpendicular to their length, but such cracking operation, after the plates are in position, is a tedious and costly process and unless it is carried out with the utmost care there is a possibility of chipping off portions of the plates during such operation.

A particular object of my invention is to eliminate the disadvantages resulting from warping of collecting electrodes formed of cementitious material and at the same time eliminate the necessity of forcibly cracking such electrodes after they are installed.

The collecting electrode ofmy invention I comprises a plurality of plate vsections of electrically semi-conducting cementitious material having their edges abutting closely against one another but unbonded', and reenforcing means common to all of said sections and embedded or cast therein. Said reenforcing means advantageously comprise a plurality of metallic reenforcing members, each extending through all of the sections and perpendicular to the abutting edges thereof and embedded in the material of which such sections are composed. Such embedded reenforcing members are preferably all connected at one end to a metallic supporting member lying along the outer edge of one of the end sections. A simple and advantageous method of making such a collecting electrode consists in first" casting alternate sections thereof. of concrete or other suitable cementitious material, with the-metallic reenforcing members embedded therein so as to leave open spaces between such alternate sect-ions, permitting such sections to attain an initial set such as to prevent firm bonding therewith of new cementitious material poured in contact therewith, and then pouring the intervening sections in theopen spaces between the sections first cast, so as to form a complete electrode plate. While the present invention relates only to the construction of the collecting electrode, it is deemed advisable, in order to clearly explain the relationshi of the several sections to one another and the manner in which they are secured together, to'also describe herein this pre-.

ferred method of making'th'e same.

7 The accom anying drawings illustrate embodiments o my invention, and referring thereto: I

Fig. 1 is a lan View of the form used in casting collecting electrodes according to my invention, with the first set of alternate sections already cast therein.

Fig. 2 is a section on line 2-2 in Fig. 3.

Fig. 3 is a section on line 33 in Fig. 1.

F Fig. 4 is a plan view of the parts shown in Fig. 5 is a section on line 5-5 in Fig. 1.

Fig. 6 is a similar view after all of the sections have been cast.

Fig. 7 is a front elevation of a completed collecting electrode in the position in which it is mounted in an electrical precipitating apparatus.

Fig. 8 is a section on line 8-8 in Fig. 7.

The form for use in casting the electrode plates may be placed on any suitable flat surface, for example, a concrete floor or plate indicated at 1. The form comprises side members 2 and end members 3 consisting, for example. of metal angle bars. The other end of the form is provided by a member 4 consisting, for example, of a metal channel member which is adapted to form the supporting member at the upper end of the nished electrode plate. Side and end members 2 and 3 may be bolted together as indicated at 6 and the end member 4 may also be bolted to side members 2 as indicated at 7. 1 also prefer to provide metallic stifi'ening members 8 consisting, for example. of metal angle bars, at the sides of the electrode plate. Suitable reenforcing means. such as a plurality of reenforcing bars or rods 9 of any suitable cross-section, for example, twisted quare rods are connected at one end to the channel member 4 as by means of nuts 11 and are disposed longitudinally within the form atsuch height as to lie substantially in the central plane of the completed plate. Said reenforcing rods terminate a short distance from the other end of the form as indicated at 12 and the two rods adjacent the sides of the form may have their ends bent outwardly so as to pass througl'i angle bars 8 as indicated at 13. A plurality of eye bolts 14 are fitted over each of the two reenforcing rods adjacent the sides of the form and pass through angle bars 8 and 2 and may be provided at their outer ends with nuts 15.

At suitable intervals along the length of the form I provide transversev form members consisting, for example, of fiat metal strips 17 lying in substantially vertical planes so as to form end walls for the first set of alternate sections to be oured. For this purpose I preferably provir e means for securely connecting said transverse form members to the side members ot the form and for permitting said transverse form members to be removed from their positions after the first set of aland above the respective reenforcing r0ds'9.

The horizontal faces of angle bars 19 are adapted to rest upon the side" members 2 of the form so as to insure that the fiat members 17 are disposed in substantially vertical planes. Said. angle bars preferably project somewhat beyond said side members and may be connected as by means of bolts 24 to spacing brackets 26 riveted or otherwise connected to said side members.

The flat strips 17 may be provided with vertical notches 27 adapted to fit over the reenforcing rods 9 when the transverse form members are placed in position. In order to prevent the concrete or other material from passing through said notches a plurality of closure members 28 may be pivotally mounted as at 29 and may be provided with por tions 31 adapted to be moved into position to close the openings provided by said notches or into position away from said notches as indicated in dotted lines at 28 in Fig. 3 so as to permit the transverse form members to be removed without interference by rods 9. The closure members 28 may all be pivotally with handle 34 whereby all of said members "may be moved at one operation into either of the two positions above mentioned.

In forming'electrode plates in the apparatus above described. the parts are first assemblcd in the positions shown in Figs. 1 to 4 inclusive. and the first set of alternate sections are then poured. With the arrange ment shown the transverse form members 17 are disposed in proper positions for casting section A, between the supporting channel 4 and the first of said transverse members, and section C between the other two of said transverse members. The concrete or other material to be used in forming the plate is poured into these two sections of the form and scraped off flush with the upper edges of the side members 2. The plate is then in the condition shown in Fig. 1.

The sections so formed are then allowed to obtain an initial set which may require varyllO ing periods. for example, from 8 to 24 hours initial set bolts 24 may be removed, closure members 28 moved to positions such as 28 and the transverse .form members may then be lifted out of their positions so as to leave the spaces between the sections first cast free for pouring the remaining sections as indicated in Fig. 5.

The remaining sections B and D are then cast in the same manner as before, so as to roduce a sectional plate as shown in Fig. 6. It should be noted that since sections A and G are permitted toassume an initial set be fore pouring sectionsB and D, the respective sets of sections will be unbonded to one another at their adjoining edges, as fresh concrete or similar material will not reduce a material firm bond with the same kind 0 after it has taken an initial set.

The entire plate is left in the form for a sufficient time to acquire the strength necessary to ermit it to be raised to 'vertical'position. l hen such strength has been acquired the side and end form members 2 and 3 are removed by disconnectingbolts 6 and 7 and nuts 15. The plate may then be lifted to an upright or vertical position, preferably by raising the end to which the supporting member 4 is connected, in the manner indicated in dottedlines at 37 in Fig. 6.

The finished plate then has the appearance shown in F igs. 7 and 8. The nuts 15 may be replaced on eye bolts 14 so'as to hold the stiffening angle bars 8 in position by con necting them to the reenforcing bars 9 at the respective sides of the plate. Such plates ,inay be mounted and supported in any suitable manner. The supporting member 4 advantageously projects beyond the sides of the plate as indicated at 38 so as to rest upon suitable supporting means, such as Z bars 39.

One advantage of the resulting collecting electrode is that the sections, while unbonded, are in close contact with one another at all points along their abutting edges, so that the reenforcing rods 9 are well protected where they pass from one section into the next. This prevents exposure of any portions of said rods to the electric field and causes the desired layer of semiconducting material to be interposed in all portions of such field. If any large cracks were left between the sections, a direct exposure of the rods 9 to the electric field would result, thus provming paths of less resistance and causing concentration of the current at these points.

Furthermore, the rods 9 constitute elongated reenforcing members, each in tensile connection throughout its length and extending vertically through all the sections of the electrode, so as to be capable of support ing tension throughout their length, and thus permitting the plate to be supported wholly from the supporting member 4 at its upper end. This construction is, therefore, to be distinguished from previously known constructions of concrete collecting electrodes, in which each electrode comprised several sections resting on top of one another and each provided with vertical reenforcing members individual to that section, and in which the reenforcing members of the several sections were in alignment with one another and interengaged in such manner as to hold the section against relative lateral displace- .ment, but without any tensile connection therebetwcen. In such prior construction it was necessary to support the collecting electrode at its lower end, while with the present construction the electrode may simply be hung from its upper end. This not only eliminates the necessity of supporting means at the lower end of the electrodes, but also facilitates the placing of the electrodes in position within the precipitator housing and their removal'therefrom if necessary.

I have also shown in Figs. 7 and 8 the relathe position of the discharge electrode means with respect to the collecting electrode means in an electrical precipitator, in order to more clearly explain the advantages of my invention. Such discharge electrode means comprise a plurality of vertical wires or fine rods 41 mounted on suitable supporting members 42 and provided at their lower ends with tensioning weights 43. Said discharge electrode means are, as shown in Fig. 8, disposed at asuitable distance from the face of the collecting electrode means, so as to set up an electrical field between said electrode means upon application of a high potential difference thereto. It is highly desirable that the spacing of the discharge electrode means from the collecting electrode be as nearly uniform throughout the electrical field as is possible in order to maintain uniform conditionsof ionization and hence of precipitation. I have indicated in dotted lines at 45 in Fig. 8 an exaggerated position of the severalsections of the collecting electrode caused by warping thereof, and Ihave also indicated in dotted lines at 46 the position which would be occopied by the collecting electrode in case of an even less degree of warping if the plate consisted of a single integral slab. It is obvious that the non-ui'iiforuiity of the electrisist of Portland cement concrete or other com The breaking of the plate along the lines between adjacent sections, in order to produce the result shown at 45 in Fig. 8, may 00- eur of its own accord due to the warping action or it may be accon'iplished forcibly if de' sired, either before or after the plates are mounted in the precipitator, but in any event only a relatively small force will be required to etlect such breaking as compared to that requiredto break an integrally cast plate.

I claim:

l. A collecting electrode for electrical precipitators comprising a plate formed of a pluralitv of sections of cementitious material disposed one above the other and having their edges in close contact with one another but unbonded. a metallic supporting member extending along the upper edge of said plate, and a plurality of metallic reenforcing members connected to said supporting member and extending vertically through all of said sections and being embedded therein and in tensile connection throughout their length.

2. A collecting electrode for electrical precipitators comprising a vertically disposed plate formed of a plurality of sections of cementitious material disposed one above the other and having their adjoining edges in close contact with one another but unbonded, and integral reenforcing means extending substantially throughout the height of said plate and embedded in all of said sections.

In testimony whereof I have hereunto subscribed my name this 2nd day of December,

CECIL B. CLYNE. 

